A wide range of medical procedures involve placing objects, such as sensors, tubes, catheters, dispensing devices, and implants, within the body. Real-time imaging methods are often used to assist doctors in visualizing the object and its surroundings during these procedures. In most situations, however, real-time three-dimensional imaging is not possible or desirable. Instead, systems for obtaining real-time spatial coordinates of the internal object are often utilized. In these systems compensation for effects of respiration may be required.
U.S. Patent Application 2009/0030307, to Govari et al., whose disclosure is incorporated herein by reference, describes a method for position tracking that includes placing an internal reference probe in a reference location within a heart of a subject, and collecting and processing location coordinates of the probe during one or more respiratory cycles so as to define a range of the location coordinates corresponding to the reference location.
U.S. Pat. No. 6,711,429, to Gilboa et al., whose disclosure is incorporated herein by reference, describes a system and method of displaying at least one point-of-interest of a body during an intra-body medical procedure. The display may be effected by monitoring and displaying the catheter's location throughout a respiratory cycle and also averaging its location over at least one respiratory cycle.
US Patent Application 2009/0182224, to Shmarak et al., whose disclosure is incorporated herein by reference, describes apparatus for generating an organ timing signal relating to an inspected organ within the body of a patient. The disclosure refers to reconstructing a respiratory trajectory.